WIP feat/code-quality: Code Quality Improvements

[johnpyp]

Description

This PR is meant to include a few different changes meant to improve code quality across the codebase (in the same spirit as the linting and formatting PR).

List of changes (subject to change):

• Improves use of plural and singular nouns to differentiate arrays vs singular items
• Improves namespace pollution to avoid often confusing variable name overriding.
• Removes some unused packages and code (#389)
• Upgrades all packages to latest version
• Changes some code structure to adhere to new 18.0 airbnb eslint config rules
• Refactors the query-string usage
• Adds a "Map View" and "Admin View" toggle button to the header to more seamlessly switch between the two.

Fixes #389 Fixes #328

Outstanding Issues

• react-google-maps throws warnings because it is using deprecated apis, addressed in issue #392
• tests are still broken (broken on development branch too)

  Motivation and Context

Code quality is important to maintain to ease development friction for existing contributors, as well as helping new contributors on-board quickly.

Type of change

• [x] Bug fix (non-breaking change which fixes an issue)

[acharliekelly]

Hey, maybe you want to split this into 2 PRs, one for each issue

[acharliekelly]

Is it possible to put the Map Toggle button in a separate PR? I think the other issues are close enough not to need their own PRs, but the more distinct PRs you have, the easier it will be to fix merge conflicts later